Styles

All those who have worked with styles and themes know that they’re hard to get right. We tend to get frustrated when we work with them. The hierarchy easily devolves into spaghetti code. How often did you want to change a style but feared you might break the continuity of the design of the app somewhere or the other. I ran into a similar situation recently. I had to change the whole app’s style’s and theme by just changing the colors etc. in one location. This was for the Open Event android project where we wanted that while generating an apk by the apk generator we could change the color scheme of the app and could make it customisable for the needs of the organisations. So, I’ll be talking about styling different views in this post. This shall be a long post! When should we use styles First of all, most of us get confused on when should we use styles instead of an inline attribute. Now I am going to show the rules that I follow: When you have multiple views that should look identical ( Perhaps that do similar things) Few Examples : Payment screens. You want to get the user through a bunch of ordering and payment screens. You need similar kind of buttons there to make it look like a continuous process. Hence we make the Buttons follow one particular style <style name="Payment_Buttons"> <item name="android:minWidth">@dimen/button_min_width</item> <item name="android:minHeight">@dimen/button_min_height</item> <item name="android:background">@color/my_choice_color</item> </style> Try to use themes to tweak default styles Themes provide a way of defining the default style of many widgets. For example : If you want to define the default button for all of your payment screens in the example above, you can do something like : <style name="ButtonTheme"> <item name="android:buttonStyle">@style/MyButton</item> </style> But note that if you’re tweaking the default style, the only tricky part is to figure out the parent of your style but that’s really dificult due to a lot of variation within the different versions of android. If you’re using something that’s part of the AppCompat, then it’s okay. you don’t need to worry about the variations but when you want to style something not in AppCompat, then the main problem arises. So For example I want a button to be Holo until kitkat and then Material starting Lollipop, I’ll do something like this : In values/styles.xml - <style name="ButtonParent" Parent = "android:Widget.Holo.Button" /> <style name="ButtonParent.Holo"> <item name="android:background">@drawable/my_bg</item> </style> Then in values-v21/styles.xml: <style name="ButtonParent" parent ="android:Widget.Material.Button/> This makes the button consistent with guidelines and the app looks perfect. Now, Themes vs Styles This is a topic which most of the developers don’t know about. They get confused on what is the difference between them. I was also not totally clear about this until recently. A theme is infact a style, the only difference is the usage. We set a theme in the Manifest of the app or an activity We set a style in a layout file or a widget There are more styles than themes (Checkout…